This invention relates to a method and device for transmitting digital data containing unusable inhibition code data.
In one aspect of transmission of digital data, there are occasions wherein input digital data are recorded and/or reproduced for transmission. In such transmission, code data which is not proper to be recorded during recording and/or reproduction, that is, inhibition code data as later described, cannot be transmitted, so that the inhibition code data are replaced by code data other than the inhibition code data prior to transmission.
That is, for recording/reproducing digital data, since it may occur that certain data portions are unable to be reproduced due to error occurrence during recording/playback, the conventional practice has been to replace during playback the data portion suffering from the error occurrence by particular code data indicating that the data portion is error data. Consequently, if the code data which are the same as the particular code data are supplied as an input and the code data which are the same as the particular code data are recorded or reproduced, it becomes impossible to decipher whether the reproduced data is the particular code data indicating an error or the input data having the same contents as the particular code data. Therefore, if the code data having the same contents as the particular code data is supplied as input data, it is necessary to render the code data unrecordable as being inhibition data.
For this reason, the conventional practice has been to record and/or reproduce input digital data for transmission after replacing the inhibition code data in the input digital data which is not to be recorded for recording/reproduction by code data which is not the inhibition code data.
There are also occasions wherein the totality of code data inclusive of the inhibition code data has to be transmitted for transmission of the digital data. However, since the conventional practice when the inhibition code data is supplied as input data has been to convert the inhibition code data simply into code data other than the inhibition code data to transmit the converted inhibition code data, the inhibition data supplied as input data becomes unable to be transmitted even in cases wherein it is necessary to transmit the totality of code data inclusive of the inhibition code data.
Consequently, if, in a system for recording/reproducing the digital data for transmission, the totality of code data inclusive of the inhibition code data are desired to be used for the purpose of recording and/or playback, such as for a data recorder, the above-described method of simply converting the inhibition code data cannot be employed.